1. Field of the Invention
This invention relates to processing responses to a broadcast.
2. Description of the Related Art
From the early days of FM broadcast transmission, stations have included ancillary signals such as background music or reading services for the blind along with a main carrier signal. The idea of transmitting data along with the main carrier signal caught on, and now many broadcast radio services either transmit an ancillary data signal or are developing a method to do so. The most current and widely used data transmission standard is the United States Radio Broadcast Data Systems (“RBDS”) standard.
The RBDS standard, published by the National Radio Systems Committee and sponsored by the Electronics Industry Association and the National Association of Broadcasters, describes a system for broadcasting a variety of program-related information on a subcarrier of a standard FM broadcast channel. The RBDS standard teaches a system for transmitting station identification and location information, as well as time, traffic and miscellaneous other information.
The RBDS standard was designed to allow stations to send information such as call letters, station format, traffic alerts and scrolling text messages to compatible radios.
Many stations installed RBDS encoders through a program encouraged by the FCC in the early 1990's that provided encoders at no charge. Radio stations that did not participate in this “RBDS Roll-Out” can still obtain encoders at competitive prices.
RBDS encoders generate what is known as a “subcarrier” that modulates along with an FM station broadcast signal and can be demodulated by special decoders. The RBDS uses a subcarrier frequency of 57 khz. Commercially available RBDS encoders usually accept information via either serial or parallel data ports and format the information into the appropriate RBDS block type.
The RBDS data signal is a specially encoded text stream containing up to 32 repeating data “groups” transmitting at 1187.5 bits/second. The RBDS data signal does not require inclusion of all potential data group blocks of both repeating and unique data. One embodiment includes using one of several groups that are designed for data transmission functions.
An RBDS data group is composed of 4 blocks, each divided by checkwords used for error correction. Block 1 is a 4-digit Program Identification code (PI) which is derived from the transmitting station's call letters. Block 2 includes a 4-bit type code and a 1-bit group version code which identifies the type of information the data group contains. This block also contains a 1-bit code that identifies the transmitting station as one that broadcasts traffic information, followed by a 5-bit Program Type (PTY) code which describes the current program or format being broadcast by the station (Rock, Oldies, Talk, News, etc.). Information contained in Blocks 3 and 4 are dependent on the codes included in Block 2. Blocks 3 and 4 provide two 16-bit data slots where specific information can be sent to the special receiver.
For example, RBDS Group types 2A, use blocks 3 and 4 to transmit a 64-character text message known as RadioText (RT). This appears on RBDS-enabled radios as a scrolling message which some stations use to identify the song or program being broadcasted. Other group types use these blocks to identify alternate frequencies where the same programming can be available, in-house station text messages, or Emergency Alert System (EAS) communication messages. An extensive description of the RBDS standard is available through the National Association of Broadcasters and the National Radio Systems Committee.
A similar standard used in Europe is the European Radio Data System (RDS).
Broadcasters using the RBDS standard can distribute information to a large number of users. However, the standard does not allow individual users to respond to the broadcast information.
Currently, users listening to the radio or watching television may particularly like a song or program that they would like to purchase. While stations using RBDS/RDS may provide a user with the station call letters or the name of the song currently being broadcast, the user has no way to purchase the media at that point. Instead, the user must write down or remember the identifying information and then go to a store or online retailer to purchase the media. Not only is this inconvenient, but the user may forget the name of the song or not be able to find a store that sells the song. Additionally, the information provided by the radio station may not be enough to sufficiently identify the song. For example, the user may have the song title, but not the artist name, album name, or other necessary identifying information. Some material, such as editorial news broadcasts or live events, may not be available for purchase or may be difficult to find. Radio stations often have fund raising drives or listener surveys that require a listener to call the station or respond within a limited time. These same problems also apply to television and other forms of broadcast media.